Potato, the third most important crop worldwide, plays a critical role in human food security. Brown rot, one of the most destructive potato diseases caused by Ralstonia solanacearum, results in huge economic losses every year. A quick, stable, low cost and high throughout method is required to meet the demands of identification of germplasm resistance to bacterial wilt in potato breeding programs. Here we present a novel R. solanacearum hydroponic infection assay on potato plants grown in vitro. Through testing wilt symptom appearance and bacterial colonization in aerial part of plants, we found that the optimum conditions for in vitro potato infection were using an OD600 0.01 bacterial solution suspended with tap water for infection, broken potato roots and an open container. Infection using R. solanacearum strains with differential degree of aggressivity demonstrated that this infection system is equally efficient as soil-drench inoculation for assessment of R. solanacearum virulence on potato. A small-scale assessment of 32 potato germplasms identified three varieties highly resistant to the pathogen, which indicates this infection system is a useful method for high-throughout screening of potato germplasm for resistance. Furthermore, we demonstrate the utility of a strain carrying luminescence to easily quantify bacterial colonization and the detection of latent infections in hydroponic conditions, which can be efficiently used in potato breeding programs. We have established a quick and efficient in vitro potato infection system, which may facilitate breeding for new potato cultivars with high resistance to R. solanacearum.

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一种快速高效的水培马铃薯感染方法评估马铃薯抗性和青枯菌毒力

马铃薯是全球第三大重要作物，在人类粮食安全中发挥着关键作用。褐腐病是由青枯菌引起的最具破坏性的马铃薯病害之一，每年都会造成巨大的经济损失。需要一种快速、稳定、低成本、高通量的方法来满足马铃薯育种项目中青枯病种质抗性鉴定的需要。在这里，我们提出了一种新的青枯菌水培感染试验，用于体外生长的马铃薯植物。通过对植物地上部分的枯萎症状表现和细菌定植情况进行测试，发现马铃薯体外侵染的最佳条件是用OD600 0.01 的自来水悬浮菌液、破碎的马铃薯根部和敞开的容器进行侵染。使用 R 感染。具有不同侵袭性的青枯菌菌株表明，这种感染系统与土壤浸种接种同样有效，可用于评估青枯菌对马铃薯的毒力。对 32 个马铃薯种质的小规模评估确定了三个对病原体具有高度抗性的品种，这表明该感染系统是高通量筛选马铃薯种质抗性的有用方法。此外，我们展示了携带发光菌株的实用性，可以轻松量化细菌定植和检测水培条件下的潜伏感染，这可以有效地用于马铃薯育种计划。我们已经建立了一个快速高效的马铃薯体外感染系统，这可能有助于培育对青枯病菌具有高抗性的马铃薯新品种。